| 摘要 |
PCT No. PCT/SE93/00994 Sec. 371 Date Dec. 5, 1995 Sec. 102(e) Date Dec. 5, 1995 PCT Filed Nov. 19, 1993 PCT Pub. No. WO94/13119 PCT Pub. Date Jun. 9, 1994The invention relates to a method and system for communicating from the secondary side of an isolation transformer (6) to receiver means, the primary of said transformer being connected via a power cable to a circuit fed with a periodic voltage from a constant-current generator, said receiver means being connected to said circuit. More particularly, switch means (30) are arranged for generating communicating signals by momentarily affecting the impedance on the secondary side so as to generate one or more voltage pulses on the primary side (8) of the transformer for propagation along the cable to said receiver means. |
